Everyone who has taken a camera under (especially in the tropics) has at some point or another run into the problem of the lens port fogging up. One of my favourite discussions brings up a lot of the reasons why your housing would fog up. Unsurprisingly it is all to do with humidity and temperatures. If you open your housing in a warm humid environment and take it in to relatively cooler temperature water you are likely to get condensation on in your housing. We tend to only notice this when it is on the port blocking our cameras view to the underwater world.

There are things we can do to counteract this and the most popular one would seem to be dry silica / desiccant packs inside the housing to absorb any moisture in the air. Some people have used tea bags (undoubtedly Americans, no Brit would waste a good tea bag!), damp towels over housings when in the sun, hair dryers and LP hose air guns. Whilst these methods of trying to stop the fogging from affecting your photo taking the best solution is to stop fogging from happening at all.

All you need to do is keep the moisture out of the housing by putting your equipment together in the driest environment you have. This could be anything from an air conditioned hotel room to a vacuum sealed chamber (ok, less likely). The point is that fogging is preventable and shouldn’t be the reason you come back from a dive with no photos.